1. Field of the Invention
The invention relates to a conical stressing device for connecting a hub to a shaft.
2. Related Art
Typical conical stressing devices are shown in German Offenlegungsschrift DE-OS No. 23 29 940 and German Patent Specification DE-PS No. 12 94 751. In DE-OS No. 23 29 940 the double conical ring is the outer ring and the individual conical rings are seated on the hub within the double conical ring. In DE-PS No. 12 94 751 the double conical ring is seated on the hub and the individual conical rings are outer rings which, during the tensioning, produce an annular tensile stress.
In both of the preceding cases, however, the double conical stressing assembly is arranged entirely on the hub. The frictional connection between the hub and the shaft, which is the determining factor for the transmission of the torque, is produced exclusively by the forcing together of the hub by the double conical stressing assembly.
Conical stressing devices are frequently employed in heavy-duty drive connections where it is necessary to avoid any possible weakening of the shaft by keyways and the resulting localized increase of stress from notch effects. The diameter of the shaft is most commonly in the region of several hundred millimeters. The hub is appropriately dimensioned so that it is able to transmit the forces taken up from the drive shaft to the driven components which are connected to it. It is necessary that the hub should not be too thick-walled because, if it is, then too much of the clamping force of the double conical stressing assembly is wasted solely on deformation of the hub. Thus, the dimensioning of the hub is critical, and can lead in practice to the output capacity of the ub being overstrained. The shearing forces arising from the transmitted torque are superimposed, in the hub, on the very considerable radial compressive forces due to the pressure exerted by the double conical stressing assembly, so that comparative streses are developed which could actually lie in the region of the yield point, or flow limit, of the material.